Hypoxis hookeri Geerinck
Small to minute tufted summer-dormant herbs. Roots mostly fibrous, a few fleshy and contractile. Corm 5-8 mm diam., seated on a stack of saucer-shaped shrunken earlier corms and surrounded by fibrous ± reticulate remains of old leaf-sheaths. Stem erect, very short. Leaves 1.5-6 cm × 1-2 mm, sheath closed; lamina narrow-linear, slightly fleshy, channelled and with rounded keel, subulate towards tip, glabrous except for minute marginal cilia. Peduncle arising from within sheath of associated leaf on side opposite lamina, sometimes as many as 6 peduncles in successive leaves; peduncle from entirely hidden within sheath to 15 mm long, with 2 opposite usually short subulate bracts; pedicels 1 or 2, 5-(20) mm long. Flower to 10 mm diam., opening only briefly; segments lanceolate, acute, the outer c. 4-6 × 1.5-2 mm, green outside and yellow inside, the inner slightly smaller, yellow. Ovary c. 2 × 1.2 mm, narrow-turbinate. Fruit 2.5-6 × 1.5-3 mm, subglobose to turbinate, contracted above into narrow neck below persistent green perianth-cone; pericarp whitish and membranous when mature; dehiscence irregularly circumscissile. Seeds c. 0 75 mm diam., black, globose, with shallow, rounded surface pattern.
N. Hawkes Bay - one collection (Colenso) locality not known; Wellington - Pencarrow (Mrs Gibbs, 1938). S. Marlborough - Wairau Awatere Rivers; Canterbury - Banks Peninsula and Canterbury Plains. Sometimes locally common in scattered east coast, S. Id localities, on very dry depleted sites, originally under low tussock grassland but now much modified by burning and heavy sheep and rabbit grazing.
(Tasmania, S. and E. Australia)
First record: Hooker 1853: 253, as "H. hygrometrica R. Br."
First collection: Hawkes Bay, Colenso, undated (K).
FL. 2-10. FT. 2-10.
Formerly treated in N.Z. as H. pusilla Hook. f. Fl. Tasm. 2, 1858, 36, t. 130 B, but Geerinck (loc. cit.) showed that this name is a later homonym of H. pusilla Kunth in H. B. and K. Nov. Gen. Sp. 1, 1816, 286.
Notwithstanding its original recording by Hooker, and the report of a different chromosome number for some Australian material (W. D. Jackson in Darlington and Wylie Chromosome Atlas 1955, 403), we consider that H. hookeri should be treated as adventive in view of its regular association here with a range of adventives of Australian origin. It may have arrived with early imported Australian seed used for oversowing, or with Australian merinos and their fodder.
H. hookeri is a summer-dormant cormous geophyte, a growth form otherwise unknown in the indigenous flora. A very small perennial, it is wholly subterranean in summer, and easily overlooked.
